Working on the cupertino nav bars recently gave me some context on those
widgets, so when I saw this
[comment](https://github.com/flutter/flutter/pull/157568#issuecomment-2590955571)
I was inspired to add a fix :)
Thanks @MaherSafadii for [starting the
exploration](https://github.com/flutter/flutter/pull/157568#issuecomment-2592535332)
and also for the very helpful
[screenshots](https://github.com/flutter/flutter/issues/162021#issuecomment-2608430023).
Removes the following when
CupertinoNavigationBar/CupertinoSliverNavigationBar is used in a
CupertinoSheetRoute:
- Unneeded back button
- Superfluous top padding in CupertinoNavigationBar
- Full page route transitions
## Before:
https://github.com/user-attachments/assets/a6da3957-0cff-4491-9380-bbc676ac799d
## After:
https://github.com/user-attachments/assets/37cd1628-a47e-44aa-85c7-abceda6e7944
<details>
<summary>Sample code</summary>
```dart
// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:flutter/cupertino.dart';
/// Flutter code sample for [CupertinoSheetRoute].
class CupertinoSheetApp extends StatelessWidget {
const CupertinoSheetApp({super.key});
@override
Widget build(BuildContext context) {
return const CupertinoApp(title: 'Cupertino Sheet', home: HomePage());
}
}
class HomePage extends StatelessWidget {
const HomePage({super.key});
@override
Widget build(BuildContext context) {
return CupertinoPageScaffold(
navigationBar: const CupertinoNavigationBar(
middle: Text('Sheet Example'),
automaticBackgroundVisibility: false,
),
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
CupertinoButton.filled(
onPressed: () {
Navigator.of(context).push(
CupertinoSheetRoute<void>(
builder: (BuildContext context) => const _SheetScaffold(),
),
);
},
child: const Text('Open Bottom Sheet'),
),
],
),
),
);
}
}
class _SheetScaffold extends StatelessWidget {
const _SheetScaffold();
@override
Widget build(BuildContext context) {
return CupertinoPageScaffold(
navigationBar: CupertinoNavigationBar(
backgroundColor: CupertinoColors.systemGrey.withOpacity(0.5),
middle: const Text('CupertinoNavigationBar Sample'),
automaticBackgroundVisibility: false,
),
child: Column(
children: <Widget>[
Container(height: 50, color: CupertinoColors.systemRed),
Container(height: 50, color: CupertinoColors.systemGreen),
Container(height: 50, color: CupertinoColors.systemBlue),
Container(height: 50, color: CupertinoColors.systemYellow),
Center(
child: CupertinoButton.filled(
onPressed: () {
Navigator.of(context).push(
CupertinoSheetRoute<void>(
builder: (BuildContext context) =>
const SliverNavBarExample(),
),
);
},
child: const Text('Open Bottom Sheet'),
),
)
],
),
);
}
}
class SliverNavBarExample extends StatelessWidget {
const SliverNavBarExample({super.key});
@override
Widget build(BuildContext context) {
return CupertinoPageScaffold(
child: CustomScrollView(
slivers: <Widget>[
const CupertinoSliverNavigationBar(
leading: Icon(CupertinoIcons.person_2),
largeTitle: Text('Contacts'),
trailing: Icon(CupertinoIcons.add_circled),
),
SliverFillRemaining(
child: Padding(
padding: const EdgeInsets.symmetric(horizontal: 10.0),
child: Column(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: <Widget>[
const Text('Drag me up', textAlign: TextAlign.center),
CupertinoButton.filled(
onPressed: () {},
child: const Text('Bottom Automatic mode'),
),
CupertinoButton.filled(
onPressed: () {},
child: const Text('Bottom Always mode'),
),
],
),
),
),
],
),
);
}
}
```
</details>
Fixes [Cupertino navbars apply too much top padding within a
sheet](https://github.com/flutter/flutter/issues/162021).
## Pre-launch Checklist
- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [ ] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.
dfb36f032e